Acute diffusion-weighted imaging lesions in cerebral amyloid angiopathy-related convexal subarachnoid hemorrhage

Small acute diffusion-weighted imaging (DWI) lesions can accompany intracerebral hemorrhage due to cerebral amyloid angiopathy (CAA). We therefore examined the occurrence of such lesions in the context of CAA-related convexal subarachnoid hemorrhage (cSAH) both in a cross-sectional and longitudinal manner. DWI lesions were noted in 14/29 (48%) patients at their index cSAH and 12/21 patients (57%) showed acute small DWI lesions at follow-up MRI. Forty-four of 71 (62%) DWI lesions were spatially related to areas of cortical superficial siderosis. Clarification of the implications of our finding needs the investigation of larger patient groups.